1. Field of the Invention
The present invention relates to (cycloalkylamino)methylenebis(phosphonic acid), lower alkyl ester thereof or pharmaceutically acceptable salts thereof which are useful as medicines having a bone resorption inhibitory effect as well as an anti-inflammatory effect and an antirheumatic effect and also relates to medicines containing the compounds as an active ingredient.
2. Description of the Related Art
Some derivatives of (cycloalkylamino)methylenebis(phosphonic acid) are known. Japanese patent laid-open No. 37,829/79 discloses compounds having an unsubstituted cyclopentyl group or a cyclohexyl group and Japanese patent publication No. 12,319/80 discloses a compound having a cyclohexyl group as the cycloalkyl group respectively. These Japanese patent gazettes mention that these compounds can be used as agricultural chemicals, especially as herbicide and that they can be use in a method for preventing precipitation in water or in aqueous solution, but are quite silent on the usability of the compounds as medicines.
An object of the present invention is to provide (cycloalkylamino)methylenebis(phosphonic acid) derivatives having unsubstituted or substituted cycloalkyl group having 3 to 10 carbon atoms and are useful for a bone-resorption inhibitor and an anti-arthritis.